Back in the early 2000s ADOT started to hear from drivers who said certain stretches of Valley freeways seemed quieter than others.
ADOT and the Maricopa Association of Governments (MAG) noticed a difference, too.
It seemed that areas paved with an asphalt rubber friction course (rubberized asphalt), which MAG funded through the Regional Transportation Plan, were less noisy than freeway surfaces with cement concrete pavement.

Much has changed since ADOT got its start in 1927.
Back then, the agency was known as the Arizona State Highway Department and roads certainly were built a little differently. Methods, materials and technology have changed so much since then.

﻿﻿﻿﻿﻿﻿﻿﻿﻿﻿﻿﻿Most people don’t find the sound of traffic especially soothing …
ADOT certainly recognizes this and is constantly working to minimize the impacts to surrounding neighborhoods from the noise of new freeways.